CVE-2025-38110
📋 TL;DR
A vulnerability in the Linux kernel's MDIO bus subsystem allows out-of-bounds read/write access when using clause 45 (C45) MDIO operations via ioctl. Attackers with local access can potentially read kernel memory or cause denial of service. This affects Linux systems with network interfaces using MDIO bus communication.
💻 Affected Systems
- Linux kernel
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory corruption leading to privilege escalation, system crash, or information disclosure of sensitive kernel data.
Likely Case
Local denial of service through kernel panic or system instability when accessing invalid memory addresses.
If Mitigated
Minimal impact with proper access controls limiting local user privileges and kernel hardening features enabled.
🎯 Exploit Status
Exploitation requires local access and knowledge of MDIO operations; no public exploit code identified yet.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 260388f79e94, 31bf7b2b9256, 4ded22f7f3ce, abb0605ca009
Vendor Advisory: https://git.kernel.org/stable/c/260388f79e94fb3026c419a208ece8358bb7b555
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to install latest kernel updates. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Restrict MDIO tool access
linuxLimit access to mdio-tools and similar utilities to trusted users only.
chmod 750 /usr/bin/mdio-tools
setfacl -m u:trusteduser:rx /usr/bin/mdio-tools
Disable unnecessary MDIO functionality
linuxRemove or disable mdio-tools if not required for system operation.
apt remove mdio-tools
yum remove mdio-tools
🧯 If You Can't Patch
- Implement strict access controls to prevent unauthorized local users from executing MDIO operations.
- Monitor system logs for unusual MDIO activity or kernel panic events related to network drivers.
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if it includes the fix commits: uname -r and examine kernel source or changelog.Check Version:
uname -rVerify Fix Applied:
After update, verify kernel version includes fix commits and test MDIO C45 operations with boundary addresses.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs mentioning MDIO, network driver crashes, or out-of-bounds memory access in dmesg
Network Indicators:
- Unusual local process accessing network PHY registers via MDIO
SIEM Query:
process.name="mdio-tools" AND event.action="ioctl"